One thing that could fix it, the analysts said: an online shopping solution that acts like Expedia for healthcare. Ideally, that could reduce waste by half or roughly $800 billion of the projected $1.6 trillion. While those tools exist in pieces, they haven't caught on in a big way or done much yet to control health spending.

"We expect the 'Healthcare Expedia' to empower people to take ownership of their care, choosing cheaper sites for care and preventative medicine," the analysts wrote.

The "Healthcare Expedia" in their eyes looks like a place where consumers can compare prices and read reviews, similar to how Expedia functions for travel shopping. It could also include ways to book and pay for the visit or treatment. The analysts said they expect the tool to start in Medicare, especially amid a more tech-friendly aging population.

The venture, announced in January 2018, is aimed at lowering healthcare costs for the companies' employees, though there haven't been many details about what that looks like. At the time, news of the partnership sent healthcare stocks plummeting, especially health insurers and members of the pharmaceutical supply chain that might be impacted by the three business giants getting into their lines of work.

Combined, Morgan Stanley noted, the three organizations provide health insurance for about 2.4 million people in the US, including workers and their families, spending an estimated $13 billion each year. While we still don't know much about what shape the joint venture will take, Morgan Stanley doesn't expect it to look like a new insurer.

"We do think that they will find a way to innovate and create the next generation of healthcare consumption," the analysts wrote.

Because of Amazon's consumer-focused background, Berkshire Hathaway's diversified employee base, and JPMorgan's experience so far with trying to drive consumers to make better healthcare decisions, the analysts argued, the three are set up to build an Expedia-like tool.

"[JPMorgan CEO] Jamie [Dimon]'s comments from JPM's February investor day suggest that one of the key areas that the joint venture is working on is data that consumers can use to better inform their decisions on where to go for what procedures, including cost and likely outcomes," the analysts wrote.

Regardless of who builds it, the "Healthcare Expedia" will go up against some big challenges.

That includes finding a way to positively change the behaviors of patients so that they can find high-quality healthcare at a lower price. One worry is that if forced to shop and spend more of their own money, patients will skip appointments or stop taking medications because they can't afford them. Research has shown that's already happening in in some health-insurance plans that require patients to spend lots of their own money on care.

Another issue is the difficulty of connecting fragmented information about patients, with doctor's offices holding one piece, insurers another, and pharmacies another. The systems often can't talk to each other, making it hard to exchange information about care or costs. Doctors, worried that patients will skimp on quality in favor of cost, are resistant to transparency tools.

Companies have attempted to build a "Healthcare Expedia" in the past. Companies like Castlight, for instance, have price-transparency tools for medical procedures, while Zocdoc has reviews for doctors and helps patients book appointments. But none yet are nearly as mainstream as travel-shopping sites like Expedia.